The present invention relates to a device for controlling equipment by detecting signals reflecting a brain function of a living body by using visible or near-infrared rays and for controlling the equipment by the signals, and in particular to an improvement on the accuracy of the controlling device.
For operation of game machines or computers there have been used input devices provided with a joy stick, a handle or a keyboard operated by muscles in accordance with the command from the brain of a living body.
On the other hand, methods of inputting commands into game machines by using brain waves have been disclosed by Japanese Patent Application Laid-Open Hei 6-296757 and Japanese Patent Application Laid-Open Hei 7-124331. But there is a problem with the methods of inputting commands into game machines by using brain waves that they handle very small electrical currents, and they are easily influenced by electrical noise signal occurring when muscles are moved, or other external noises.
To solve this problem, Japanese Patent Application Laid-Open Hei 9-149894 discloses a method of optically measuring the change of the flow of blood in the brain reflecting the activity of the brain, and using the obtained information on the degree of the brain activation for the purpose of inputting commands into various kinds of equipment.
When a keyboard or a handle is used for operating a game machine or a computer or inputting data into the game machine or the computer, it is easy to confirm the movement of the body for inputting the command to equipment, or to confirm if the data or the control data has been input into the equipment as intended. Therefore, if the data or the control data was not input into the equipment as intended, they can be corrected immediately.
On the other hand, the information on the degree of the brain activation is used for inputting data or as controlling signals, and it was difficult to confirm immediately if the data or the control data has been input into the equipment as intended. The prior art device is not configured such that change in the degree of the brain activation was not perceived by the possessor of the brain.
When light was used to extract characteristics of the brain as signals, it was difficult to separate the intended signals from the other signals because the source for the intended signals are surrounded by some structures or organs of the living body, and consequently the obtained signals could not be used directly as data into equipment or as a controlling signal for the equipment.
Further the blood flow in the brain optically measured as the information on the degree of the brain activation is susceptible to heart beats or the autonomic nervous system, and signals corresponding to the change of the blood flow in the skin caused by thermoregulation are superposed on the signals corresponding to the degree of the brain activation. In the method by measuring the change of the blood flow in the brain, the signals reflecting the degree of the brain activation is superposed with unwanted signals produced by the change of the blood flow other than the blood flow in the brain. The unwanted signals are an obstacle to obtaining the actual signals for the degree of the brain activation and cause malfunction of the equipment supplied with the unwanted signals. The prior art device is not configured such that change in the degree of the brain activation was not perceived by the possessor of the brain.